PALYNZIQ

Pegvaliase-pqpz is a phenylalanine-metabolizing enzyme that is composed of recombinant phenylalanine ammonia lyase (rAvPAL) conjugated to N-hydroxysuccinimide (NHS)-methoxypolyethylene glycol (PEG). rAvPAL is manufactured in Escherichia coli bacteria transformed with a plasmid containing the phenylalanine ammonia lyase (PAL) gene derived from Anabaena variabilis . During the rAvPAL manufacturing process, fermentation is carried out in nutrient medium containing the antibiotic kanamycin. However, kanamycin is cleared in the manufacturing process and is not detectable in the final product. rAvPAL is a homotetrameric protein with a molecular weight of 62 kD per monomer. To produce pegvaliase-pqpz, an average of nine (9) 20 kD PEG molecules are covalently bound (or conjugated) to each monomer of rAvPAL. The total molecular weight of pegvaliase‑pqpz (rAvPAL‑PEG) is approximately 1000 kD. Palynziq (pegvaliase‑pqpz) injection, intended for subcutaneous injection, is a clear to slightly opalescent, colorless to pale yellow, sterile, preservative-free solution and is formulated at pH 6.6 to 7.4. Palynziq is provided in a single-dose prefilled syringe and is available in three dosage strengths: 2.5 mg/0.5 mL, 10 mg/0.5 mL, and 20 mg/mL. Palynziq contents for each dosage strength are summarized in Table 4. Table 4: Contents of Palynziq Strength Total Contents per Prefilled Syringe Palynziq 2.5 mg/0.5 mL prefilled syringe 2.5 mg pegvaliase-pqpz (expressed as the amount of rAvPAL conjugated to 7.25 mg of 20 kD PEG in 0.5 mL Water for Injection, USP) and contains the following inactive ingredients: sodium chloride (for tonicity adjustment), trans-cinnamic acid (0.07 mg), and tromethamine and tromethamine hydrochloride (for pH adjustment). Palynziq 10 mg/0.5 mL prefilled syringe 10 mg pegvaliase-pqpz (expressed as the amount of rAvPAL conjugated to 29 mg of 20 kD PEG in 0.5 mL Water for Injection, USP) and contains the following inactive ingredients: sodium chloride (for tonicity adjustment), trans-cinnamic acid (0.07 mg), and tromethamine and tromethamine hydrochloride (for pH adjustment). Palynziq 20 mg/mL prefilled syringe 20 mg pegvaliase-pqpz (expressed as the amount of rAvPAL conjugated to 58 mg of 20 kD PEG in 1 mL Water for Injection, USP) and contains the following inactive ingredients: sodium chloride (for tonicity adjustment), trans-cinnamic acid (0.15 mg), and tromethamine and tromethamine hydrochloride (for pH adjustment).

Palynziq is indicated to reduce blood phenylalanine concentrations in adult patients with phenylketonuria (PKU) who have uncontrolled blood phenylalanine concentrations greater than 600 micromol/L on existing management. Palynziq is a phenylalanine (Phe)‑metabolizing enzyme indicated to reduce blood Phe concentrations in adult patients with phenylketonuria who have uncontrolled blood Phe concentrations greater than 600 micromol/L on existing management. ( 1 )

Dosage ( 2.1 ) Obtain baseline blood Phe concentration before initiating treatment. The recommended initial dosage is 2.5 mg subcutaneously once weekly for 4 weeks. Titrate the dosage in a step-wise manner over at least 5 weeks based on tolerability to achieve a dosage of 20 mg once daily. See full prescribing information for titration regimen. Assess patient tolerability, blood Phe concentration, and dietary protein and Phe intake throughout treatment. Consider increasing the dosage to 40 mg once daily in patients who have been on 20 mg once daily continuously for at least 24 weeks and who have not achieved blood Phe control (blood phenylalanine concentration less than or equal to 600 micromol/L). Consider increasing the dosage to a maximum of 60 mg once daily in patients who have been on 40 mg once daily continuously for at least 16 weeks and who have not achieved blood Phe control. Discontinue Palynziq in patients who have not achieved an adequate response after 16 weeks of continuous treatment with the maximum dosage of 60 mg once daily. Reduce the dosage and/or modify dietary protein and Phe intake, as needed, to maintain blood Phe concentrations within a clinically acceptable range and above 30 micromol/L. Blood Phenylalanine Monitoring and Diet ( 2.2 ) Obtain blood Phe concentrations every 4 weeks until a maintenance dosage is established. Periodically monitor blood Phe concentrations during maintenance therapy. Counsel patients to monitor dietary protein and Phe intake, and adjust as directed by their healthcare provider. Premedication ( 2.3 , 5.1 , 5.3 ) Consider premedication for hypersensitivity reactions. Administration Instructions ( 2.4 ) Rotate injection sites. If more than one injection is needed for a single dose, the injection sites should be at least 2 inches away from each other. 2.1 Dosage Treatment with Palynziq should be managed by a healthcare provider experienced in the management of PKU. Obtain baseline blood phenylalanine concentration before initiating treatment. Induction The recommended initial induction dosage for Palynziq is 2.5 mg subcutaneously once weekly for 4 weeks. Administer the initial dose under the supervision of a healthcare provider [see Dosage and Administration ( 2.4 )]. Titration Titrate the Palynziq dosage in a step-wise manner, based on tolerability, over at least 5 weeks, to achieve a dosage of 20 mg subcutaneously once daily according to Table 1. Maintenance Therapeutic response may not be achieved until the patient is titrated to an effective maintenance dosage of Palynziq. Use the lowest effective and tolerated dosage of Palynziq. Assess patient tolerability, blood phenylalanine concentrations, and dietary protein and phenylalanine intake throughout treatment. Individualize the maintenance dosage to achieve blood phenylalanine control (blood phenylalanine concentrations less than or equal to 600 micromol/L), taking into account patient tolerability to Palynziq and dietary protein intake (see Table 1). Maintain the Palynziq dosage at 20 mg once daily for at least 24 weeks. Consider increasing the Palynziq dosage to 40 mg once daily in patients who have been on 20 mg once daily continuously for at least 24 weeks without achieving blood phenylalanine control. Consider increasing the Palynziq dosage to a maximum of 60 mg once daily in patients who have been on 40 mg once daily continuously for at least 16 weeks without achieving blood phenylalanine control. Discontinuation Discontinue Palynziq in patients who have not achieved an adequate response after 16 weeks of continuous treatment with the maximum dosage of 60 mg once daily [see Clinical Studies ( 14 )]. Table 1: Recommended Dosing Regimen Treatment Palynziq Dosage Duration Additional time may be required prior to each dosage escalation based on patient tolerability. Induction 2.5 mg once weekly 4 weeks Titration 2.5 mg twice weekly 1 week 10 mg once weekly 1 week 10 mg twice weekly 1 week 10 mg four times per week 1 week 10 mg once daily 1 week Maintenance Individualize treatment to the lowest effective and tolerated dosage. Consider increasing to 40 mg once daily in patients who have not achieved a response with 20 mg once daily continuous treatment for at least 24 weeks. Consider increasing to a maximum of 60 mg once daily in patients who have not achieved a response with 40 mg once daily continuous treatment for at least 16 weeks [see Clinical Studies (14)]. 20 mg once daily 24 weeks 40 mg once daily 16 weeks Maximum Discontinue Palynziq in patients who have not achieved an adequate response after 16 weeks of continuous treatment at the maximum dosage of 60 mg once daily. 60 mg once daily 16 weeks Dose Reduction for Low Phenylalanine Concentrations During titration and maintenance of Palynziq treatment, patients may experience blood phenylalanine concentrations below 30 micromol/L. For blood phenylalanine concentrations below 30 micromol/L, the dosage of Palynziq may be reduced and/or dietary protein and phenylalanine intake may be modified to maintain blood phenylalanine concentrations within a clinically acceptable range and above 30 micromol/L [see Dosage and Administration ( 2.2 )] . Readministration Following Anaphylaxis If the decision is made to readminister Palynziq after an anaphylaxis episode, administer the first dose following the anaphylaxis episode under the supervision of a healthcare provider equipped to manage anaphylaxis and closely observe the patient for at least 60 minutes following the dose. Subsequent dose titration should be based on patient tolerability and therapeutic response [see Warnings and Precautions ( 5.1 )] . Missed Dose If a dose is missed, instruct patients to take their next dose as scheduled and to not take two doses of Palynziq to make up for the missed dose. 2.2 Blood Phenylalanine Monitoring and Diet After initiating treatment with Palynziq, obtain blood phenylalanine concentrations every 4 weeks until a maintenance dosage is established. After a maintenance dosage is established, periodic blood phenylalanine monitoring is recommended to assess blood phenylalanine control. Monitor patients’ dietary protein and phenylalanine intake throughout treatment with Palynziq and counsel them on how to adjust their dietary intake, as needed, based on blood phenylalanine concentrations. 2.3 Premedication For hypersensitivity reactions, consider premedication with an H 1 ‑receptor antagonist, H 2 ‑receptor antagonist, and/or antipyretic prior to Palynziq administration based upon individual patient tolerability [see Warnings and Precautions ( 5.1 , 5.3 )] . 2.4 Administration Instructions Each prefilled syringe of Palynziq is intended for use as a single subcutaneous injection. Inspect Palynziq visually for particulate matter and discoloration prior to administration. Palynziq is a clear to slightly opalescent, colorless to pale yellow solution. Discard if discolored, cloudy, or if particulate matter is present. Prior to first dose of Palynziq, prescribe auto-injectable epinephrine, and instruct the patient and observer (if applicable) on how to recognize the signs and symptoms of anaphylaxis, how to properly administer auto-injectable epinephrine, and to seek immediate medical care upon its use. Perform initial administration(s) and/or readministration after an anaphylaxis episode under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection [see Warnings and Precautions ( 5.1 )] . Prior to self-injection, confirm patient competency with self‑administration. Consider having an adult observer for patients who may need assistance in recognizing and managing anaphylaxis during Palynziq treatment. If an adult observer is needed, the observer should be present during and for at least 60 minutes after each Palynziq administration, should be able to administer auto-injectable epinephrine, and to call for emergency medical support upon its use [see Warnings and Precautions ( 5.1 )] . The recommended injection sites for Palynziq are: the front middle of thighs and the abdomen at least 2 inches (five centimeters) away from the navel. If a caregiver is giving the injection, the top of buttocks and the back of the upper arms are also appropriate injection sites. Do not inject Palynziq into moles, scars, birthmarks, bruises, rashes, or areas where the skin is hard, tender, red, damaged, burned, inflamed, or tattooed. Check the injection site for redness, swelling, or tenderness. Rotate sites for subcutaneous injections of Palynziq. If more than one injection is needed for a single dose of Palynziq, the injection sites should be at least 2 inches away from each other. The second injection site can be on the same part of the body or a different part of the body. 2.1 Dosage Treatment with Palynziq should be managed by a healthcare provider experienced in the management of PKU. Obtain baseline blood phenylalanine concentration before initiating treatment. Induction The recommended initial induction dosage for Palynziq is 2.5 mg subcutaneously once weekly for 4 weeks. Administer the initial dose under the supervision of a healthcare provider [see Dosage and Administration ( 2.4 )]. Titration Titrate the Palynziq dosage in a step-wise manner, based on tolerability, over at least 5 weeks, to achieve a dosage of 20 mg subcutaneously once daily according to Table 1. Maintenance Therapeutic response may not be achieved until the patient is titrated to an effective maintenance dosage of Palynziq. Use the lowest effective and tolerated dosage of Palynziq. Assess patient tolerability, blood phenylalanine concentrations, and dietary protein and phenylalanine intake throughout treatment. Individualize the maintenance dosage to achieve blood phenylalanine control (blood phenylalanine concentrations less than or equal to 600 micromol/L), taking into account patient tolerability to Palynziq and dietary protein intake (see Table 1). Maintain the Palynziq dosage at 20 mg once daily for at least 24 weeks. Consider increasing the Palynziq dosage to 40 mg once daily in patients who have been on 20 mg once daily continuously for at least 24 weeks without achieving blood phenylalanine control. Consider increasing the Palynziq dosage to a maximum of 60 mg once daily in patients who have been on 40 mg once daily continuously for at least 16 weeks without achieving blood phenylalanine control. Discontinuation Discontinue Palynziq in patients who have not achieved an adequate response after 16 weeks of continuous treatment with the maximum dosage of 60 mg once daily [see Clinical Studies ( 14 )]. Table 1: Recommended Dosing Regimen Treatment Palynziq Dosage Duration Additional time may be required prior to each dosage escalation based on patient tolerability. Induction 2.5 mg once weekly 4 weeks Titration 2.5 mg twice weekly 1 week 10 mg once weekly 1 week 10 mg twice weekly 1 week 10 mg four times per week 1 week 10 mg once daily 1 week Maintenance Individualize treatment to the lowest effective and tolerated dosage. Consider increasing to 40 mg once daily in patients who have not achieved a response with 20 mg once daily continuous treatment for at least 24 weeks. Consider increasing to a maximum of 60 mg once daily in patients who have not achieved a response with 40 mg once daily continuous treatment for at least 16 weeks [see Clinical Studies (14)]. 20 mg once daily 24 weeks 40 mg once daily 16 weeks Maximum Discontinue Palynziq in patients who have not achieved an adequate response after 16 weeks of continuous treatment at the maximum dosage of 60 mg once daily. 60 mg once daily 16 weeks Dose Reduction for Low Phenylalanine Concentrations During titration and maintenance of Palynziq treatment, patients may experience blood phenylalanine concentrations below 30 micromol/L. For blood phenylalanine concentrations below 30 micromol/L, the dosage of Palynziq may be reduced and/or dietary protein and phenylalanine intake may be modified to maintain blood phenylalanine concentrations within a clinically acceptable range and above 30 micromol/L [see Dosage and Administration ( 2.2 )] . Readministration Following Anaphylaxis If the decision is made to readminister Palynziq after an anaphylaxis episode, administer the first dose following the anaphylaxis episode under the supervision of a healthcare provider equipped to manage anaphylaxis and closely observe the patient for at least 60 minutes following the dose. Subsequent dose titration should be based on patient tolerability and therapeutic response [see Warnings and Precautions ( 5.1 )] . Missed Dose If a dose is missed, instruct patients to take their next dose as scheduled and to not take two doses of Palynziq to make up for the missed dose. 2.2 Blood Phenylalanine Monitoring and Diet After initiating treatment with Palynziq, obtain blood phenylalanine concentrations every 4 weeks until a maintenance dosage is established. After a maintenance dosage is established, periodic blood phenylalanine monitoring is recommended to assess blood phenylalanine control. Monitor patients’ dietary protein and phenylalanine intake throughout treatment with Palynziq and counsel them on how to adjust their dietary intake, as needed, based on blood phenylalanine concentrations. 2.3 Premedication For hypersensitivity reactions, consider premedication with an H 1 ‑receptor antagonist, H 2 ‑receptor antagonist, and/or antipyretic prior to Palynziq administration based upon individual patient tolerability [see Warnings and Precautions ( 5.1 , 5.3 )] . 2.4 Administration Instructions Each prefilled syringe of Palynziq is intended for use as a single subcutaneous injection. Inspect Palynziq visually for particulate matter and discoloration prior to administration. Palynziq is a clear to slightly opalescent, colorless to pale yellow solution. Discard if discolored, cloudy, or if particulate matter is present. Prior to first dose of Palynziq, prescribe auto-injectable epinephrine, and instruct the patient and observer (if applicable) on how to recognize the signs and symptoms of anaphylaxis, how to properly administer auto-injectable epinephrine, and to seek immediate medical care upon its use. Perform initial administration(s) and/or readministration after an anaphylaxis episode under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection [see Warnings and Precautions ( 5.1 )] . Prior to self-injection, confirm patient competency with self‑administration. Consider having an adult observer for patients who may need assistance in recognizing and managing anaphylaxis during Palynziq treatment. If an adult observer is needed, the observer should be present during and for at least 60 minutes after each Palynziq administration, should be able to administer auto-injectable epinephrine, and to call for emergency medical support upon its use [see Warnings and Precautions ( 5.1 )] . The recommended injection sites for Palynziq are: the front middle of thighs and the abdomen at least 2 inches (five centimeters) away from the navel. If a caregiver is giving the injection, the top of buttocks and the back of the upper arms are also appropriate injection sites. Do not inject Palynziq into moles, scars, birthmarks, bruises, rashes, or areas where the skin is hard, tender, red, damaged, burned, inflamed, or tattooed. Check the injection site for redness, swelling, or tenderness. Rotate sites for subcutaneous injections of Palynziq. If more than one injection is needed for a single dose of Palynziq, the injection sites should be at least 2 inches away from each other. The second injection site can be on the same part of the body or a different part of the body.

None. None. ( 4 )

The following serious adverse reactions are discussed below and in other sections of labeling: Anaphylaxis [see Warnings and Precautions ( 5.1 )] Other Hypersensitivity Reactions [see Warnings and Precautions ( 5.3 )] Most common adverse reactions (at least 20% in either treatment phase) are: injection site reactions, arthralgia, hypersensitivity reactions, headache, generalized skin reactions lasting at least 14 days, nausea, abdominal pain, vomiting, cough, oropharyngeal pain, pruritus, diarrhea, nasal congestion, fatigue, dizziness, and anxiety. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact BioMarin Pharmaceutical Inc. at 1-866-906-6100, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect a total treatment exposure of 789 patient-years in 285 patients who received Palynziq in an induction/titration/maintenance regimen in clinical trials [see Clinical Studies ( 14 )] . Of the 285 patients, 229 patients were exposed to Palynziq for 24 weeks, 209 patients were exposed for 1 year, 181 patients were exposed for 2 years, and 160 patients were exposed for 3 years or longer. The patient population was evenly distributed between male and female patients, the mean age was 29 years (range: 16 to 56 years), and 98% of patients were White. The most common adverse reactions (at least 20% of patients in either treatment phase) were injection site reactions, arthralgia, hypersensitivity reactions, headache, generalized skin reactions lasting at least 14 days, nausea, abdominal pain, vomiting, cough, oropharyngeal pain, pruritus, diarrhea, nasal congestion, fatigue, dizziness, and anxiety. Of the 285 patients exposed to Palynziq in an induction/titration/maintenance regimen in clinical trials, 44 (15%) patients discontinued treatment due to adverse reactions. The most common adverse reactions leading to treatment discontinuation were hypersensitivity reactions (6% of patients) including anaphylaxis (3% of patients), angioedema (1% of patients), arthralgia (4% of patients), generalized skin reactions lasting at least 14 days (2% of patients), and injection site reactions (1% of patients). The most common adverse reactions leading to dosage reduction were arthralgia (15% of patients), hypersensitivity reactions (9% of patients), injection site reactions (4% of patients), alopecia (3% of patients), and generalized skin reactions lasting at least 14 days (2% of patients). The most common adverse reactions leading to temporary drug interruption were hypersensitivity reactions (14% of patients), arthralgia (13% of patients), anaphylaxis (4% of patients), and injection site reactions (4% of patients). Table 2 lists adverse reactions reported in at least 15% of patients treated with Palynziq in an induction/titration/maintenance dosage regimen in clinical trials, and illustrates the adverse reaction rates over time by treatment phase. Table 3 lists laboratory abnormalities reported in at least 10% of patients treated with Palynziq in an induction/titration/maintenance dosage regimen in clinical trials. For these analyses, the induction/titration phase was defined as the time prior to reaching a stable dose (completing an 8‑week phase at the same dose level). Once a stable dosage was reached, patients were considered to be in the maintenance phase thereafter. Safety data for patients who reached the maintenance phase are included within either the induction/titration or maintenance phases depending on the onset date of the adverse reaction. Safety data for patients who did not reach the maintenance phase are included within the induction/titration phase. The maintenance phase includes data for patients who were previously on Palynziq and transitioned to placebo during the randomized withdrawal period of Study 302 [see Clinical Studies ( 14 )]. Rates of adverse reactions (adjusted for duration of exposure) generally decreased over time and for some stayed relatively stable. In the maintenance phase, the rate of adverse reactions (adjusted for duration of exposure) in patients who reached the maintenance phase was comparable across dosages evaluated. The types and rate of adverse reactions reported during the maintenance phase in patients who received 20 mg once daily, 40 mg once daily, and 60 mg once daily were similar. During long-term treatment (greater than 36 months), the exposure-adjusted rates of adverse reactions decreased. Rates of laboratory abnormalities (adjusted for duration of exposure) stayed relatively stable over time, except for complement C4 below lower limit of normal (LLN) and hs-CRP above 0.287 mg/dL over a 6 month period (both decreased over time) and hypophenylalaninemia (blood phenylalanine concentration below 30 micromol/L) on a single measurement (increased over time). There were no dose‑related trends in type or rate of laboratory abnormalities (adjusted for duration of exposure) reported during the maintenance phase in patients receiving 20 mg once daily, 40 mg once daily, or 60 mg once daily. Table 2: Adverse Reactions ≥ 15% incidence in either treatment phase Reported in at least 15% of PKU Patients Treated with Palynziq in an Induction/Titration/Maintenance Regimen in Clinical Trials – Incidence and Exposure-Adjusted Rates Treatment Phase Treatment Duration Induction/Titration Phase (N = 285) 141 person-years Mean: 188 days Median: 116 days Range: 1 to 2266 days Maintenance Phase (N = 225) 652 person-years Mean: 1087 days Median: 1158 days Range: 5 to 2017 days Adverse Reaction N (%) N (%) = Number of patients with at least 1 Adverse Reaction (%); Rate = Exposure-Adjusted Rate of Adverse Reactions (Adverse Reactions/Person‑Years) Episodes (Rate) N (%) Episodes (Rate) Injection site reactions Includes injection site: reaction, erythema, pruritus, pain, bruising, rash, swelling, urticaria, induration, hemorrhage, edema, mass, inflammation, nodule, discoloration, warmth, hematoma, irritation, vesicles, hypersensitivity, papule, discomfort, scar, paresthesia, hypertrophy, extravasation, dryness, scab 252 (88%) 2965 (21) 166 (74%) 2169 (3.3) Arthralgia Includes arthralgia, pain in extremity, back pain, musculoskeletal pain, neck pain 211 (74%) 1049 (7.4) 154 (68%) 893 (1.4) Hypersensitivity reactions Includes rash, urticaria, anaphylaxis, rash generalized, hypersensitivity, rash erythematous, rash maculo-papular, rash pruritic, serum sickness, swelling face, dermatitis contact, swollen tongue, lip swelling, rash macular, pharyngeal edema, injection site hypersensitivity, eczema, drug eruption, dermatitis allergic, dermatitis, tongue edema, palatal edema, edema mouth, multiple allergies, lip edema, eye edema, exfoliative rash, drug hypersensitivity, dermatitis atopic, dermatitis acneiform, pruritus allergic, mouth swelling, implant site rash, gingival swelling, face edema, eyelid edema, eye swelling, dermatitis psoriasiform, dermatitis infected, conjunctivitis allergic, bronchospasm, angioedema, allergic sinusitis, allergic cough, eczema nummular, rhinitis allergic 153 (54%) 634 (4.5) 145 (64%) 845 (1.3) Headache Includes headache, migraine, sinus headache 102 (36%) 214 (1.5) 126 (56%) 1049 (1.6) Generalized skin reaction lasting at least 14 days Includes pruritus, rash, urticaria, dry skin, rash erythematous, erythema, cellulitis, rash macular, pruritus generalized, petechiae, dermatitis allergic, skin infection, skin induration, rash maculo-papular, rash generalized, pharyngeal edema, macule, granulomatous dermatitis, exfoliative rash, drug eruption, dermatitis atopic, dermatitis, xanthogranuloma, skin plaque, skin mass, skin lesion, skin hypopigmentation, skin hyperpigmentation, skin exfoliation, septal panniculitis,scar, rash pruritic, rash papular, psoriatic arthropathy, pruritus allergic, papule, necrobiosis lipoidica diabeticorum, furuncle, eczema, ecchymosis, dermatitis psoriasiform, dermatitis infected, blister, eczema nummular, granuloma, infected dermal cyst, lipohypertrophy, psoriasis, skin irritation 61 (21%) 97 (0.7) 93 (41%) 186 (0.3) Nausea 52 (18%) 68 (0.5) 69 (31%) 141 (0.2) Abdominal pain Includes abdominal pain, abdominal pain upper, abdominal discomfort 39 (14%) 54 (0.4) 67 (30%) 162 (0.3) Vomiting 36 (13%) 53 (0.4) 68 (30%) 139 (0.2) Cough 27 (9%) 33 (0.2) 67 (30%) 100 (0.2) Oropharyngeal pain 38 (13%) 45 (0.3) 65 (29%) 108 (0.2) Pruritus 58 (20%) 102 (0.7) 61 (27%) 424 (0.7) Diarrhea 26 (9%) 32 (0.2) 61 (27%) 116 (0.2) Nasal congestion 12 (4%) 16 (0.1) 61 (27%) 87 (0.1) Fatigue 37 (13%) 81 (0.6) 55 (24%) 110 (0.2) Dizziness 47 (16%) 65 (0.5) 48 (21%) 100 (0.2) Anxiety 14 (5%) 23 (0.2) 48 (21%) 100 (0.2) Alopecia 13 (5%) 14 (0.1) 43 (19%) 62 (0.1) Table 3: Laboratory Abnormalities Reported in at least 10% of PKU Patients Treated with Palynziq in an Induction/Titration/Maintenance Regimen in Clinical Trials – Incidence and Exposure-Adjusted Rates Treatment Phase Treatment Duration Induction/Titration Phase (N = 285) 141 person‑years Mean: 188 days Median: 116 days Range: 1 to 2266 days Maintenance Phase (N = 225 ) 652 person‑years Mean: 1087 days Median: 1158 days Range: 5 to 2017 days Laboratory Measurement N (%) N (%) = Number of patients with at least 1 laboratory abnormality (%); Rate = Exposure-Adjusted Rate of Laboratory Abnormalities (Laboratory Abnormalities/Person‑Years) Episodes (Rate) N (%) Episodes (Rate) Complement factor C3 below LLN 195 (68%) 453 (3.2) 188 (84%) 2259 (3.5) C-reactive protein (CRP) above ULN 182 (64%) 359 (2.5) 160 (71%) 1414 (2.2) Hypophenylalaninemia Blood phenylalanine concentration below 30 micromol/L on a single measurement 53 (19%) 216 (1.5) 147 (65%) 1553 (2.4) Complement factor C4 below LLN 177 (62%) 318 (2.3) 111 (49%) 714 (1.1) Hypophenylalaninemia on 2 or more consecutive measurements 45 (16%) 62 (0.4) 111 (49%) 204 (0.3) Blood creatine phosphokinase (CPK) above ULN 50 (18%) 88 (0.6) 108 (48%) 377 (0.6) Hs-CRP above 0.287 mg/dL over a 6 month period 34 (12%) 34 (0.4) 36 (16%) 46 (0.1) LLN – lower limit of normal ULN – upper limit of normal Hs – high sensitivity Description of Selected Adverse Reactions Arthralgia In clinical trials, 245 out of 285 (86%) patients experienced episodes consistent with arthralgia (includes back pain, musculoskeletal pain, pain in extremity, and neck pain). Arthralgia episodes were more frequent during the induction/titration phase (7.4 episodes/patient-year) and decreased over time (1.4 episodes/patient-year in the maintenance phase). Forty-four out of 285 (15%) patients had one episode of arthralgia, 32 (11%) patients had 2 episodes of arthralgia, 18 (6%) had 3 episodes of arthralgia, and 146 (51%) had 4 or more episodes of arthralgia. Arthralgia occurred as early as after the first dose of Palynziq and occurred at any time during treatment. The mean duration of arthralgia was 16 days (median: 3 days, range: 1 to 936 days), and 19% of arthralgia episodes had a duration of at least 14 days. Severe arthralgia (severe pain limiting self-care activities of daily living) was reported by 11 (4%) patients. In addition to arthralgia, other joint-related signs and symptoms reported were: joint swelling (24 patients; 8%), joint stiffness (22 patients; 8%), and musculoskeletal stiffness (20 patients; 7%). Arthralgia episodes were managed with medications (e.g., nonsteroidal anti-inflammatory drugs, glucocorticoids, and acetaminophen), Palynziq dosage reduction (4% of episodes), Palynziq interruption (4% of episodes), or Palynziq withdrawal (0.6% of episodes). 97% of arthralgia episodes were reported as resolved at the time of last observation (up to 77 months of follow‑up). Injection Site Reactions Injection site reactions were reported as early as after the first dose of Palynziq and occurred at any time during treatment. Injection site reactions were more frequent during the induction/titration phase (21 episodes/patient-years) and decreased over time (3 episodes/patient‑years in the maintenance phase). The mean duration of injection site reaction was 10 days (median: 2 days, range: 1 to 1612 days), and 8% of injection site reactions had a duration of at least 14 days. 99% of injection site reactions were reported as resolved at the time of last observation (up to 77 months of follow‑up). Three injection site reactions consistent with granulomatous skin lesions were reported (each reaction occurring in one patient): granulomatous dermatitis (occurred after 464 days of Palynziq treatment and lasted 16 days), xanthogranuloma (occurred after 378 days of Palynziq treatment and lasted 638 days) was treated with a topical antihistamine, corticosteroid, and Palynziq treatment was discontinued, and necrobiosis lipoidica diabeticorum (occurred after 281 days of Palynziq treatment and lasted 281 days). Necrobiosis lipoidica diabeticorum was treated with steroid injections and complicated by Pseudomonas infection. All three injection site reactions resolved. One patient reported soft tissue infection (occurred after 196 days of Palynziq treatment and lasted 8 days) associated with mesenteric panniculitis treated with antibiotics, which resulted in treatment discontinuation. Generalized Skin Reactions (not limited to the injection site) Lasting at Least 14 Days In clinical trials, 134 out of 285 (47%) patients treated with Palynziq experienced generalized skin reactions (not limited to the injection site) lasting at least 14 days. Mean duration of these reactions was 63 days (median: 37 days; range: 14 to 638 days). Generalized skin reactions were more frequent during the induction/titration phase (0.7 episodes/patient‑years), and decreased over time (0.3 episodes/patient-years in the maintenance phase). The mean time from first dose of Palynziq to onset of skin reactions was 373 days (median: 213 days; range: 2 to 1970 days). 5% of these reactions persisted at least 180 days, and 86% of these reactions were reported as resolved at the time of last observation (up to 77 months of follow‑up). Angioedema In clinical trials, 22 out of 285 (8%) patients experienced 45 episodes of angioedema (symptoms included: pharyngeal edema, swollen tongue, lip swelling, mouth swelling, eyelid edema and face edema) occurring independent of anaphylaxis. Angioedema (included under Hypersensitivity in Table 2) was more frequent during the induction/titration phase (0.14 episodes/patient-year) and decreased over time (0.04 episodes/patient-year in the maintenance phase). Three patients discontinued treatment. All episodes resolved. Angioedema can present as a symptom of anaphylaxis [see Warnings and Precautions ( 5.1 )]. Serum Sickness In clinical trials, serum sickness was reported in 7 out of 285 (2%) patients. Serum sickness episodes were more frequent during the induction/titration phase (0.04 episodes/patient-year) and decreased over time (less than 0.01 episodes/patient-year during the maintenance phase). All serum sickness reactions resolved without sequelae (duration of serum sickness ranged from 1 to 8 days). Out of the 7 patients who experienced serum sickness, 5 patients continued treatment without a recurrence, and managed serum sickness with drug interruption, dosage reduction and/or concomitant medication. Two patients discontinued treatment. 6.2 Post-Marketing Experience The following adverse reactions have been identified during post-approval use of Palynziq. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Administration site conditions : injection site infection, cellulitis, necrosis, and abscess. 6.3 Immunogenicity As with all therapeutic proteins, there is potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors, including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to Palynziq in the studies described below with the incidence of antibodies in other studies or to other products may be misleading. All patients treated with Palynziq developed a sustained total anti-drug antibody (TAb) response with a majority of patients (91%; N = 235/258) developing that response by Week 4 of treatment. Mean TAb titers peaked 2 weeks after Palynziq initiation and remained elevated throughout treatment (greater than 3 years after treatment initiation). Anti-phenylalanine ammonia lyase (PAL) IgM antibodies were detected in a majority of patients (98%; N = 265/270) by 2 months after treatment initiation, with incidence declining over time to 67% at 36 months (N = 114/171). Anti‑PAL IgG antibodies were detected in almost all patients (N = 226/227) by 4 months after treatment initiation. Mean anti-PAL IgM and IgG titers peaked at approximately 3 and 6 months, respectively, after treatment initiation and remained elevated throughout treatment (greater than 3 years after treatment initiation). Drug-induced anti-PEG IgM and IgG antibodies were detected in the majority of patients (98%; N = 277/284 for IgM; and 278/284 for IgG) with mean titers for both peaking at 1 to 3 months after treatment initiation [see Drug Interactions ( 7.1 )] . Neutralizing antibodies (NAb) capable of inhibiting PAL enzyme activity were detected on at least one measurement in the majority of patients (89%; N = 253/284) over time. Mean NAb titers peaked and reached a plateau at 16 to 20 weeks of treatment and then remained present throughout treatment (greater than 3 years after treatment initiation). Twenty-seven of 29 patients who had anaphylaxis were tested for anti‑pegvaliase‑pqpz IgE antibodies, which recognize the PEGylated protein product. Of the 27 patients tested for anti‑pegvaliase‑pqpz IgE antibodies, 26 patients tested negative. The one patient who tested positive for anti‑pegvaliase‑pqpz IgE antibodies on the screening test did not have sufficient sample to confirm IgE positivity. This patient tested negative for anti‑pegvaliase‑pqpz IgE at routine visits prior to and after the anaphylaxis episode (not at times of anaphylaxis). Sixty‑seven of 285 patients in clinical trials were tested for both anti‑PAL IgE antibodies, which recognize the recombinant PAL protein, and for anti‑pegvaliase‑pqpz IgE antibodies during routine study visits (not at times of anaphylaxis episodes) or during additional visits for hypersensitivity reactions. Of those 67 patients, 5 (8%) tested positive at least once for anti‑PAL IgE antibodies but negative for anti‑pegvaliase‑pqpz IgE antibodies. The highest frequency of hypersensitivity reactions (consistent with a Type III immune complex-mediated hypersensitivity mechanism) occurred within the first 6 months of Palynziq treatment when the mean circulating immune complex (CIC) concentrations were at their highest and mean complement C3 and C4 concentrations were at their lowest. Mean CIC concentrations decreased and complement levels increased over time as the exposure-adjusted rate of hypersensitivity reactions decreased. IgG and IgM CIC concentrations were above the upper limit of normal in 63% (N = 164/259) and 42% of patients (N = 109/259), respectively, at 12 weeks of Palynziq treatment and returned towards baseline with long-term treatment (greater than 3 years after treatment initiation). 61% of patients (N = 110/180) had complement C3 concentrations less than lower limit of normal (LLN) at 6 months after treatment initiation and 38% of patients (N = 94/248) had complement C4 concentrations less than LLN at 3 months after treatment initiation. The incidence of low complement C3 and C4 concentrations decreased over time, but approximately 35% (N = 34/96) and 12% (N = 11/96) of patients had low C3 and C4 concentrations, respectively, at 36 months after treatment initiation. Higher antibody responses for all antibody analytes, including NAb, were associated with lower mean trough pegvaliase‑pqpz concentrations and with higher blood phenylalanine concentrations. Hypersensitivity reactions occurred more frequently in patients with higher antibody titers for some but not all antibody analytes. Patients with higher mean change in IgG CIC concentrations from pre-treatment baseline tended to have higher discontinuation rates than patients with lower mean change in IgG CIC concentrations. Mean antibody titers for anti‑PAL IgG and IgM, TAb, and NAb remained relatively stable with long-term treatment.

Effect of Palynziq on Other PEGylated Products : Monitor for hypersensitivity reactions, including anaphylaxis, with concomitant treatment. ( 7.1 ) 7.1 Effect of Palynziq on Other PEGylated Products In a single dose study of Palynziq in adult patients with PKU, two patients receiving concomitant injections of medroxyprogesterone acetate suspension (a formulation containing PEG 3350) experienced a hypersensitivity reaction. One of the two patients experienced a hypersensitivity reaction on day 15 after a single Palynziq dosage of 0.67 mg within 15 minutes following medroxyprogesterone acetate injectable suspension, and subsequently experienced anaphylaxis on day 89 within 30 minutes after the next dose of medroxyprogesterone acetate injectable suspension. The other patient experienced a hypersensitivity reaction on day 40 after a single Palynziq dosage of 0.08 mg within 10 minutes following medroxyprogesterone acetate injectable suspension. Both patients had high anti‑PEG IgG antibody titers at or around the time of the hypersensitivity reactions. In Palynziq clinical trials, the majority of patients developed anti‑PEG IgM and IgG antibodies after treatment with Palynziq [see Adverse Reactions ( 6.2 )] . The clinical effects of concomitant treatment with different PEGylated products is unknown. Monitor patients treated with Palynziq and concomitantly with other PEGylated products for hypersensitivity reactions including anaphylaxis. 7.1 Effect of Palynziq on Other PEGylated Products In a single dose study of Palynziq in adult patients with PKU, two patients receiving concomitant injections of medroxyprogesterone acetate suspension (a formulation containing PEG 3350) experienced a hypersensitivity reaction. One of the two patients experienced a hypersensitivity reaction on day 15 after a single Palynziq dosage of 0.67 mg within 15 minutes following medroxyprogesterone acetate injectable suspension, and subsequently experienced anaphylaxis on day 89 within 30 minutes after the next dose of medroxyprogesterone acetate injectable suspension. The other patient experienced a hypersensitivity reaction on day 40 after a single Palynziq dosage of 0.08 mg within 10 minutes following medroxyprogesterone acetate injectable suspension. Both patients had high anti‑PEG IgG antibody titers at or around the time of the hypersensitivity reactions. In Palynziq clinical trials, the majority of patients developed anti‑PEG IgM and IgG antibodies after treatment with Palynziq [see Adverse Reactions ( 6.2 )] . The clinical effects of concomitant treatment with different PEGylated products is unknown. Monitor patients treated with Palynziq and concomitantly with other PEGylated products for hypersensitivity reactions including anaphylaxis.